Field of the Invention
The present disclosure relates to motor control apparatuses that control sensorless motors.
Description of the Related Art
Japanese Patent Laid-Open No. 2012-130100 discloses a motor control apparatus for a sensorless motor in which a phase sensor, such as a Hall sensor, that detects the phase of the rotor is not used in motor control. Motor control apparatuses for sensorless motors find the phase of the rotor from a voltage applied to the motor and a coil current.
Because the phase of the rotor is found from a voltage applied to the motor and a coil current in a sensorless motor, the phase of the rotor cannot be detected when the rotor is stopped, for example. As such, in a sensorless motor, forced driving that drives the motor is carried out using a synchronization signal of a predetermined frequency until the phase of the rotor can be detected, and the driving is then switched to normal sensorless driving, or in other words, stationary driving. In sensorless motors, there is demand for stability in the rotation of the rotor during such transitions.